1. Field of the Invention
The present invention relates to an image processing method and an image reading method in which an image exposed onto a photosensitive material for photographing is read digitally, and on the basis of the read digital image, an image is processed.
2. Description of the Related Art
In recent years, a method has been known in which an image formed on a color negative film serving as a photosensitive material for photographing is read photoelectrically and is then subjected to image processing so as to form image data for recording, so that an image is obtained on another image recording material using this image data. In particular, a digital printer is advanced in which the above-described image data serves as a digital signal, a photosensitive material such as a color paper or the like is scan-exposed by laser light modulated in accordance with the digital signal, and a finished print is formed. An example of the digital printer is described in Japanese Patent Application Laid-Open (JP-A) No. 7-15593.
Here, it is assumed that the photographed color negative film is subjected to ordinary developing, bleaching, and fixing processings (wet processing) so as to form an image, and that thus the image forming process is complicated.
As a result, the present applicants propose an apparatus for forming an image on a heat development photosensitive material by heating the heat development photosensitive material in a state in which the photosensitive material and a processing member (containing mordant) are laminated (e.g., Japanese Patent Application Laid-Open (JP-A) No. 9-304906).
According to the proposal, an image can be formed on a heat development photosensitive material, onto which an image has been exposed, by a simple method without effecting on complicated developing, bleaching, and fixing processings carried out in the conventional method. Because liquid which contains agent such as a processing solution or the like is not used, the maintenance performance of the machine can be improved.
However, when the image is read under the same conditions regardless of the type of color negative film, the color density is different and optimal digital image data cannot be obtained. As a result, complicated calibration must be carried out for each color negative film. There is a drawback in that it takes an enormous amount of time to read the image and that work efficiency is lowered.
With the aforementioned in view, an object of the present invention is to obtain an image processing method and an image reading method in which, when images are read under the same conditions for each photosensitive material for photographing, digital image data which is suitable for each of the photosensitive materials for photographing can be obtained by a simple calibration processing.
A first aspect of the present invention is an image processing method, comprising the steps of: exposing a calibration pattern outside the image exposure area of a photosensitive material for photographing before or after the image is exposed onto the photosensitive material for photographing; digitally reading the formed image and the calibration pattern after development processing and creating digital image data and digital calibration pattern data; and on the basis of the created digital calibration pattern data, correcting the digital image data.
In accordance with the first aspect of the present invention, the calibration pattern is exposed beforehand onto the photosensitive material for photographing. The exposure area is outside the image exposure area at the time of photographing.
In this way, when the photosensitive material for photographing, onto which the calibration information has been exposed, is subjected to development processing, the calibration pattern serving as the calibration information is processed together with the photographic image.
After the development processing, the formed photographic image and the formed image based on the calibration pattern are read digitally.
Next, the digital image data of the read photographic image is corrected on the basis of the digitized digital calibration pattern data.
Due to the correction, when the digital image data is used and subjected to print/exposure on a photographic printing paper or the like after the correction, the optical system such as a light source can be standardized.
A second aspect of the present invention is an image processing method, comprising the steps of: exposing a calibration pattern outside the image exposure area of a photosensitive material for photographing before or after the image is exposed onto the photosensitive material for photographing; digitally reading the formed image and the calibration pattern after development processing and creating digital image data and digital calibration pattern data; converting the created digital calibration pattern data into data which does not depend on the characteristics of the photosensitive material for photographing; and on the basis of the converted data, correcting the digital image data.
In a third aspect of the present invention, the data which does not depend on the characteristics of the photosensitive material for photographing is the amount of exposure during photographing.
In accordance with the second aspect of the present invention, the calibration pattern is exposed based on the characteristic of the standard amount of exposure/density. Consequently, when there is a difference between the data to be referenced and the digital calibration pattern data which is read after development, the difference is caused by the characteristic of the photosensitive material for photographing. In order to remove the difference, the pattern is converted into data which does not depend on the characteristics of the photosensitive material for photographing, and thereafter, the image data is corrected. In this way, more accurate correction which does not depend on the photosensitive material for photographing can be made.
As described in the third aspect of the present invention, the amount of exposure during photographing is suitable as data which does not depend on the characteristic of the photosensitive material for photographing.
In a fourth aspect of the present invention, when the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is only a constant which does not affect the inclination of the characteristics, a predetermined single gradation of at least one of gray and the respective colors R, G, B is exposed.
In accordance with the fourth aspect of the present invention, when the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is only a constant which does not affect the inclination of the characteristics, a predetermined single gradation of gray or the respective colors R, G, B is exposed as the calibration pattern. Because only the characteristic curve of the photosensitive material for photographing is shifted with respect to the characteristic curve to be referenced, only one dot of the predetermined gradation of gray or the respective colors R, G, B may be exposed. For example, if gray (halftone) is used, a determination is made as to how far the formed image deviates from gray, and the amount of deviation is operated. The result of the operation is reflected in the digital image data. In this way, even if the types of photosensitive materials for photographing are different, the digital image data to be referenced is formed ultimately. Thereafter, when the digital image data is used and subjected to print/exposure onto a photographic printing paper or the like, an optical system such as a light source or the like can be standardized.
In a fifth aspect of the present invention, when the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is a coefficient which affects the inclination of the characteristics, a predetermined plurality of gradations of gray or respective colors R, G, B or a predetermined range of continuous gradations of gray or respective colors R, G, B is exposed.
In accordance with the fifth aspect of the present invention, when the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is a coefficient which affects the inclination of the characteristics, a predetermined plurality of gradations of gray or respective colors R, G, B or a predetermined range of continuous gradations of gray or respective colors R, G, B is exposed. In this case, the larger the number of the exposed gradations, the better the accuracy, however, the longer the processing time. The most optimal number of gradations is selected so as to keep the balance between the accuracy and the processing time. For example, in an area which does not depend on the amount of exposure of the photosensitive material for photographing (a portion having a flat inclination), the number of gradations within the area may be reduced and a correction coefficient may be selected so as to form a linear area.
In a sixth aspect of the present invention, if which it cannot be determined as to whether the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is a coefficient which does affect the inclination of the characteristics or a constant which does not affect the inclination thereof, a predetermined plurality of gradations of an arbitrary color or a predetermined range of continuous gradations of an arbitrary color is exposed.
In accordance with the sixth aspect of the present invention, if it cannot be determined as to whether the difference between the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied and the characteristic of the amount of exposure/density to be referenced is a constant which does not affect the inclination of the characteristics or a coefficient which does affect the inclination of the characteristics, the converted data may be memorized in a lookup table or the like as non-linear data.
A seventh aspect of the present invention is an image reading method, comprising the steps of: exposing a calibration pattern outside the image exposure area of a photosensitive material for photographing before or after the image is exposed onto the photosensitive material for photographing; digitally reading the formed image and the calibration pattern after development processing and creating digital image data and digital calibration pattern data; and adding the calibration pattern to the digital image data so as to be output.
In accordance with the seventh aspect of the present invention, because the image data is corrected ultimately in the above-described first through sixth aspects, the formed print image is only the image which has been corrected.
In an eighth aspect of the present invention, if the photosensitive material for photographing is taken up in a roll form and accommodated within a predetermined cartridge, the exposure area of the calibration pattern of the photosensitive material for photographing is provided at an end portion which is close to the cartridge core.
Namely, it is preferable if the photosensitive material for photographing is a photographic film which is taken up in a layer form in a cartridge or the like, since the exposure area is provided at the trailing end portion thereof which is less likely to be exposed.
In a ninth aspect of the present invention, the calibration pattern is selected from a plurality of calibration patterns stored in advance by reading an identification marking (a bar code or the like) which specifies the photosensitive material for photographing.
Further, for example, in the case of an APS (advanced photo system)photographic film, since the information which specifies the photographic film is recorded onto a magnetic recording layer, this magnetic information may be read.
In a tenth aspect of the present invention, when the predetermined range of continuous gradations is exposed, the density is continuously changed by using a light source which can be modulated.
In an eleventh aspect of the present invention, when the correction coefficient of the digital image data is set for a plurality of areas, the area, in which the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied does not depend on the amount of exposure of the photosensitive material for photographing, is set wide and the area, in which the characteristic does depend on the amount of exposure of the photosensitive material for photographing, is set narrow.
In a twelfth aspect of the present invention, when the correction coefficient of the digital image data is set for a plurality of areas, the when the characteristic of the amount of exposure/density of the photosensitive material for photographing to be applied is non-linear, an area is set with predetermined restriction.
In a thirteenth aspect of the present invention, the formed image data and the corrected image data are separately recorded onto an exterior recording medium.
In accordance with the thirteenth aspect of the present invention, in recent years, image processing can be easily effected individually by a personal computer. In order to cope with this, the image data and the corrected data can be delivered to a customer as they are.
As a result, the customer can individually effect desirable image processing and print images by using the image data and the corrected data which they have received.